Solved Problem with new Visual Studio update 2017 Version 15.9.4 and Qt 5.9.3

[Doctor G]

I have read the fix suggested in this forum titled: [https://forum.qt.io/topic/93711/problem-with-new-visual-studio-update-2017-version-15-8-0-and-qt-5-9-5](link url)

It involved using a patched version of "qalgorithms.h", however that does not work for me.

I am still getting the error:

Error (active)	E2512	the argument to a feature-test macro must be a simple identifier
in qcompilerdetection.h

with Qt version Qt 5.9.3 (I cannot change the QT version, I am creating a DLL plugin for an very large program from a 3rd party).

and VS Studio 15.9.4 (notice the higher version of VS2017).

BTW, the solution was created by cmake and it says the C++ compiler is:
MSVC 19.16.27025.1

[Doctor G]

I replace the qalgorithms.h cleaned the cmake cache, did a full rebuild. And now it is working for me also.

I am using VS2017 15.9.4 and doing a x64 build with release symbols.

The only odd thing I see, is that if there are any compile errors (other than these, then the E2512 error returns also. But that sort of behavior I see a lot with microsoft VC++ compiler, so don't sweat it.

[jsulm]

@Doctor-G According to https://en.wikipedia.org/wiki/Microsoft_Visual_C%2B%2B both versions you posted mean VS2017

[Christian Ehrlicher]

@Doctor-G said in Problem with new Visual Studio update 2017 Version 15.9.4 and Qt 5.9.3:

Error (active) E2512 the argument to a feature-test macro must be a simple identifier
in qcompilerdetection.h

On which line exactly?

[primem0ver]

I am having this same problem. For me it is occurring on lines 1349 and 1351:

#if QT_HAS_CPP_ATTRIBUTE(clang::fallthrough) //1349
#    define Q_FALLTHROUGH() [[clang::fallthrough]]
#elif QT_HAS_CPP_ATTRIBUTE(gnu::fallthrough) //1351
#    define Q_FALLTHROUGH() [[gnu::fallthrough]]
#elif QT_HAS_CPP_ATTRIBUTE(fallthrough)
#  define Q_FALLTHROUGH() [[fallthrough]]
#endif

[Christian Ehrlicher]

https://forum.qt.io/topic/93711/problem-with-new-visual-studio-update-2017-version-15-8-0-and-qt-5-9-5

[Doctor G]

I replace the qalgorithms.h cleaned the cmake cache, did a full rebuild. And now it is working for me also.

I am using VS2017 15.9.4 and doing a x64 build with release symbols.

The only odd thing I see, is that if there are any compile errors (other than these, then the E2512 error returns also. But that sort of behavior I see a lot with microsoft VC++ compiler, so don't sweat it.

[Doctor G]

@primem0ver I was getting the errors on these same lines.

[lmaster]

Time : 2019/3/7 16:38
vs2017 Enterprise 15.9.2
qt version ： 12.1

what's wrong with me ...........

[EDIT: Email removed --JKSH]

[JWSchuetz]

I had the same problem. Touching the header-file "qcompilerdetection.h" and recompilation solved the problem for me.